If it’s not your experience, then I would look at your interview skills.
Your resume only gets you a conversation, you have to sell yourself to them.
Are you confident when you interview? Not too confident to be cocky though, but enough that you know what you are talking about if someone were to ask a question.
Ask questions during the interview. Ask them what they like about working there. Act interested and engaged and you will stand out among the rest.
See if your ISP can set their router to bridged mode, then you should be able to use your own while plugged into their equipment. It will turn all the functionality off on it so you won’t be doubled natted and traffic should flow properly.